'astronautically' originates from Modern English, specifically the word 'astronautical', where Greek 'astron' meant 'star' and Greek 'nautēs' meant 'sailor'.

'astronautically' changed from the adjective 'astronautical' (formed by adding the suffix '-ical' to 'astronaut'); 'astronaut' itself is a 20th-century coinage from Greek roots 'astron' + 'nautēs', and the adverb was formed by adding the adverbial suffix '-ly'.

Initially the roots referred literally to 'star-sailor' (a person who sails among the stars); over time the family of words came to mean 'relating to space travel or the technology of operating spacecraft', and 'astronautically' now means 'in a manner relating to astronautics or space travel'.